Method of manufacturing resin molded article, method of manufacturing resin composition, resin molded article, resin composition, resin powder having low dust generation property, and method of reducing dust generation of resin

ABSTRACT

A method of manufacturing a resin molded article includes a step of preparing a resin powder having low dust generation property by adding a liquid paraffin to a thermosetting resin, and a step of obtaining a resin molded article by heating and kneading the resin powder having low dust generation property, in which the step of preparing the resin powder having low dust generation property includes a step in which the thermosetting resin is melted and the liquid paraffin is added to the melted thermosetting resin to be stirred and mixed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of copending application No.14/379,672, filed on Aug. 19, 2014, which is a §371 National StageApplication of PCT International Application No. PCT/JP2013/000799 filedon Feb. 14, 2013, which is based on Japanese priority application No.2012-050015 filed on Mar. 7, 2012 and Japanese priority application No.2012-236736 filed on Oct. 26, 2012, the entire contents of which arehereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a method of manufacturing a resinmolded article, a method of manufacturing of a resin composition, aresin molded article, a resin composition, a resin powder having lowdust generation property, and a method of reducing the dust generationof a resin.

BACKGROUND ART

A method of reducing the dust generation of a fine powder or a powder isas follows.

In Patent Document 1, a treatment method of reducing the dust generationof a fine powder which is easily scattered as a powder dust during anoperation of slaked lime, dolomite, calcium carbonate, cement, gypsum,slag, magnesium hydroxide, or the like, is described. Specifically, anattempt of reducing the dust generation of the fine powder is performedby mixing a branched polyethyleneimine solution with respect to the finepowder.

In Patent Document 2, a method of reducing the dust generation of apowder such as quicklime, light burnt dolomite, cement, gypsum, slag,coke powder or diatomaceous earth, of which the quality is changed byadding water, is described. Specifically, an attempt of reducing thedust generation of a fine powder is performed by mixing a branchedpolyethyleneimine solution in which an organic solvent is used as asolvent with a powder.

As described in Patent Documents 1 and 2, there is a method ofsuppressing the dust generation property of a powder-like low molecularweight compound. However, for example, there has been no method ofsuppressing the dust generation of a powder-like high molecular weightcompound such as a resin until now.

Among high molecular weight compounds, it is known that as to athermosetting resin, the polarity of the thermosetting resin is high andit is hard to be mixed with a compound which is generally used as alubricant.

RELATED DOCUMENT Patent Document

-   [Patent Document 1] Japanese Unexamined Patent Publication No.    10-226780-   [Patent Document 2] Japanese Unexamined Patent Publication No.    11-80712-   [Patent Document 3] Japanese Unexamined Patent Publication No.    2011-214002

DISCLOSURE OF THE INVENTION

A thermosetting resin is usually used in a powder state. At this time,there is a problem in that since the thermosetting resin is in a powderyshape, the dust is generated and easily diffused to the periphery. In acase where the dust is generated from the thermosetting resin when used,the resin is sprinkled in an operation space, and for example,sometimes, the operation space was polluted, a powder-like resin wasmixed into an operation device, and a resin was mixed into otherreagents.

The present inventors found that it is possible to suppress the dustgeneration from the powder-like resin by adding a liquid paraffin withrespect to the thermosetting resin in order to solve the above problem,and reached the present invention.

A liquid paraffin is generally added as a lubricant which improves thefluidity or the releasability of the resin when the thermoplastics resinis heated and molded. On the other hand, it is known that thethermosetting resin is not used together with such a lubricant since thefluidity thereof considerably decreases by heating.

The present invention has been made in view of the above circumstancesand is to provide a resin powder in which the dust generation propertyis suppressed when used.

According to the present invention, there is provided a method ofmanufacturing a resin molded article including, a step of preparing aresin powder having low dust generation property by adding a liquidparaffin to a thermosetting resin, and a step of obtaining a resinmolded article by heating and kneading the resin powder having low dustgeneration property, in which the step of preparing the resin powderhaving low dust generation property includes a step in which thethermosetting resin is melted and the liquid paraffin is added to themelted thermosetting resin to be stirred and mixed.

It is possible to suppress the dust generation property of the resinpowder obtained by adding the liquid paraffin with respect to thethermosetting resin. The reason is not necessarily clear, however, it isconsidered as follows. When the liquid paraffin is added to thethermosetting resin, the static electricity is generated. Thus, it isconsidered that it is possible to suppress the rising of the fineparticles since an electrostatic attraction acts between the fineparticles.

In addition, the thermosetting resin is preferably a phenol resin or anepoxy resin, and the liquid paraffin preferably includes acycloparaffin. In doing so, it becomes easier to uniformly mix thethermosetting resin with the liquid paraffin.

Furthermore, according the present invention, there is provided a methodof manufacturing a resin composition including, a step of preparing aresin powder having low dust generation property containing athermosetting resin and a liquid paraffin, and a step of obtaining aresin composition by dry mixing the resin powder having low dustgeneration property with a filler.

Furthermore, according to the present invention, there is provided aresin composition obtained by the method of manufacturing the resincomposition.

Furthermore, according to the present invention, there is provided amethod of manufacturing a resin molded article including, a step ofobtaining a resin molded article from the resin composition obtained bythe method of manufacturing the resin composition.

Furthermore, according to the present invention, there is provided aresin molded article obtained by the method of manufacturing the resinmolded article.

Furthermore, according to the present invention, there is provided aresin powder having low dust generation property including, athermosetting resin and a liquid paraffin, in which the average particlediameter is equal to or more than 1 μm and equal to or less than 100 μm.

Furthermore, according to the present invention, there is provided amethod of reducing dust generation of a resin, in which case, when onecup of a resin measured out by using a 100 cc plastic cup is droppedfrom lm above the ground at 25° C., an amount of dust generation of aresin powder obtained by adding a liquid paraffin into a meltedthermosetting resin is reduced compared to a resin obtained withoutadding the liquid paraffin into the melted thermosetting resin.

According to the present invention, a resin powder in which the dustgeneration property is suppressed when used can be provided.

DESCRIPTION OF EMBODIMENTS First Embodiment

A method of manufacturing a resin molded article according to thepresent embodiment is a method of preparing a resin powder having lowdust generation property by adding a liquid paraffin to a thermosettingresin, and afterward, obtaining a resin molded article by heating andkneading the resin powder having low dust generation property. Inaddition, in a case of preparing the resin powder having low dustgeneration property, the resin powder having low dust generationproperty is obtained by a method as described below. It is possible toobtain the resin powder having low dust generation property by meltingthe thermosetting resin and adding the liquid paraffin to the meltedthermosetting resin to be stirred and mixed.

In the present embodiment, the low dust generation property indicatesthat the powder is hardly risen to the periphery when a powder-likeresin is used. That is, the resin powder having low dust generationproperty indicates a resin powder in which the resin is hardly risen inan operation space when used.

Specifically, according to the resin powder having low dust generationproperty according to the present embodiment, it is possible to reducethe amount of the dust generation of the resin powder obtained by addingthe liquid paraffin into the melted thermosetting resin when a cup ofthe resin is measured out by using a 100 cc plastic cup to drop from 1 mabove the ground at 25° C. compared to a case of not adding the liquidparaffin.

Firstly, description will be given of a method of manufacturing a resinpowder having low dust generation property in detail.

(Method of Manufacturing Resin Powder having Low Dust GenerationProperty)

The resin powder having low dust generation property can be obtained bymixing the thermosetting resin with the liquid paraffin.

As a method of manufacturing a resin powder having low dust generationproperty, for example, there is a method described below. Firstly, thethermosetting resin is melted, the melted thermosetting resin and theliquid paraffin are stirred and mixed, and a resin mixture is obtained.Next, the resin powder having low dust generation property is obtainedby pulverizing the obtained resin mixture. In doing so, it is possibleto obtain the resin powder in which the thermosetting resin and theliquid paraffin are finely dispersed. That is, it is possible touniformly and finely disperse the thermosetting resin and the liquidparaffin in the resin powder having low dust generation property to becompounded.

The mixing temperature of the thermosetting resin and the liquidparaffin is preferably equal to or more than 80° C. and equal to or lessthan 250° C. It becomes easier to uniformly mix the thermosetting resinwith the liquid paraffin by mixing in a range of this temperature.

Moreover, when the thermosetting resin is mixed with the liquidparaffin, it is possible to suppress the dust generation property of theobtained resin powder by mixing these components as uniformly aspossible.

In addition, it is preferable to add equal to or more than 0.05% byweight and equal to or less than 2% by weight of the liquid paraffin andit is more preferable to add equal to or more than 0.1% by weight andequal to or less than 1% by weight of the liquid paraffin, with respectto the total weight of the thermosetting resin. It is possible tofurther suppress the dust generation property of the obtained resinpowder owing to the additive amount of the liquid paraffin being in thisrange.

Moreover, in a case of pulverizing the resin mixture obtained by mixingthe thermosetting resin with the liquid paraffin, the average particlediameter of the obtained resin powder having low dust generationproperty is non-uniform, however, it is possible to cause a uniformelectrostatic interaction by uniformizing the particle diameter using asieve. In this manner, it is possible to further suppress the dustgeneration property of the obtained resin powder by uniformizing theparticle diameter. The average particle diameter of the resin powderhaving low dust generation property is equal to or more than 1 μm andequal to or less than 500 μm, preferably equal to or more than 1 μm andequal to or less than 100 μm and more preferably equal to or more than 5μm and equal to or less than 100 μm. It is possible to further suppressthe dust generation property of the obtained resin powder owing to theaverage particle diameter of the resin powder having low dust generationproperty being in this range.

(Method of Manufacturing of Resin Molded Article)

Next, description will be given of a method of manufacturing a resinmolded article from the resin powder having low dust generation propertyobtained by the method describe above.

In the present embodiment, it is possible to manufacture a resin moldedarticle by heating and kneading the resin powder having low dustgeneration property to be molded into the desired shape. As a resinmolded article, for example, a grindstone, a casting, a frictionmaterial, a rubber molded article, an adhesive tape, a felt, a moldmaterial, a heat resistance material, a heat insulating agent and thelike are included, however, the resin molded article is not limitedthereto.

In addition, when the resin powder having low dust generation propertyis heated and kneaded, a filler may be appropriately added in accordanceto the use of the resin molded article.

In addition, heating and kneading may be performed by a kneader alonesuch as, for example, a roll, a cokneader or a twin-screw extruder ormay be performed by combining another kneader with a roll.

(Resin Powder having Low Dust Generation Property)

The resin powder having low dust generation property according to thepresent embodiment includes the thermosetting resin and the liquidparaffin. In doing so, it is possible to obtain the resin powder inwhich the dust generation property is suppressed when used. The reasonis not necessarily clear, however, it is considered as follows. When theliquid paraffin is added to the thermosetting resin, the staticelectricity is generated. The charging quantity of the powder isimproved in accordance with the generation of the static electricity.That is, an electrostatic attraction acts between the fine particlesforming the powder by an electric charge. The rising of each fineparticle generated when the powder is used is suppressed due to thisforce, and thus it is considered that the dust generation property isalso suppressed.

The average particle diameter of the resin powder having low dustgeneration property according to the present embodiment is equal to ormore than 1 μm and equal to or less than 500 μm, preferably equal to ormore than 1 μm and equal to or less than 100 μm and more preferablyequal to or more than 5 μm and equal to or less than 100 μm. It ispossible to further suppress the dust generation property of theobtained resin powder owing to the average particle diameter of theresin powder having low dust generation property being in this range.

The thermosetting resin in the present embodiment is not particularlylimited, however, for example, phenol resins, epoxy resins, melamineresins, urea resins, oxetane resins, (meth)acrylate resins, unsaturatedpolyester resins, diallyl phthalate resins, maleimide resins, and thelike are included. In addition, these can also be used alone or incombination of two or more kinds thereof. Among those, phenol resins orepoxy resins are preferable.

In a case where a phenol resin or an epoxy resin is used, it is possibleto further uniformize a mixing degree with the liquid paraffin.Therefore, it is possible to further suppress the dust generationproperty of the obtained resin powder.

The phenol resin in the present embodiment is one obtained by reactingphenols with aldehydes in the presence of an alkaline or acidiccatalyst, and has at least one or more phenolic hydroxyl groups in anaromatic ring. Moreover, a method of reacting phenols with aldehydes isnot particularly limited, and a well-known method can be employed.

As a phenol resin, for example, a phenol resin, a cresol resin, aresorcin resin, a xylenol resin, a naphthol resin, a bisphenol A resin,an aralkyl phenol resin, a biphenylaralkyl phenol resin, a modifiedphenol resin by cashew nuts oil or the like having a phenolic hydroxylgroup, and the like are included. In addition, various kinds of modifiedphenol resins such as a xylene-modified phenol resin containing asubstance having a phenolic hydroxyl group, an oil-modified phenol resinmodified with phenols and a rosin, terpene oil or the like or arubber-modified phenol resin modified with a rubber, or the like canalso be used.

As phenols used to obtain the phenol resin, one having a phenolichydroxyl group in an aromatic ring is preferable, furthermore, phenolsmay have a substituent except a phenolic hydroxyl group. For example,phenol, cresol such as o-cresol, m-cresol or p-cresol, mixed cresol,xylenol such as 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol,3,4-xylenol or 3,5-xylenol, ethylphenol such as o-ethylphenol,m-ethylphenol or p-ethylphenol, isopropylphenol, butylphenol such asbutylphenol or p-tert-butylphenol, alkylphenol such as p-tert-amylphenol p-octylphenol, p-nonylphenol or p-cumylphenol, halogenated phenolsuch as fluorophenol, chlorophenol, bromophenol or iodophenol, amonovalent phenol substitution product such as p-phenyl phenol, aminophenol, nitrophenol, dinitrophenol or trinitrophenol, a monovalentnaphthol such as 1-naphthol or 2-naphthol, polyphenols such as resorcin,alkyl resorcin, pyrogallol, catechol, alkyl catechol, hydroquinone,alkyl hydroquinone, phloroglucin, bisphenol A, bisphenol F, bisphenol E,bisphenol S or dihydroxy naphthalene, cashew nuts oil configured by asubstance having a phenolic hydroxyl group, and the like are included.These can be used alone or in combination of two or more kinds thereof.In addition, a copolymer of these phenols having a phenolic hydroxylgroup with another substance which does not contain a phenolic hydroxylgroup may be used. From this, it is possible to obtain the phenol resinhaving at least one or more phenolic hydroxyl groups in a molecule.

In addition, as aldehydes used to obtain the phenol resin, for example,formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde,polyoxymethylene, chloral, hexamethylenetetramine, furfural, glyoxal,n-butyraldehyde, caproaldehyde, allyl aldehyde, benzaldehyde,crotonaldehyde, acrolein, tetraoxymethylene, phenyl acetaldehyde,o-tolualdehyde, salicylaldehyde, para-xylene dimethyl ether and the likeare included. These can also be used alone or in combination of two ormore kinds thereof.

The catalyst in case of obtaining the phenol resin is not particularlylimited, and an acid catalyst, a base catalyst, a transition metal saltcatalyst and the like are included. As an acid catalyst, for example, aninorganic acid such as hydrochloric acids, sulfuric acids or phosphoricacids, or an organic acid such as oxalic acid, p-toluenesulfonic acid ororganic phosphonic acid can be used. In addition, as a base catalyst,for example, an alkali metal hydroxide such as sodium hydroxide,potassium hydroxide or lithium hydroxide, an alkaline earth metalhydroxide such as calcium hydroxide or barium hydroxide, amines such asammonia or alkyl amine, or the like can be used. Furthermore, as atransition metal salt catalyst, for example, zinc oxalate, zinc acetate,and the like are included.

In addition, as an epoxy resin, for example, a novolac type epoxy resinsuch as a phenol novolac type epoxy resin or a cresol novolac type epoxyresin; a bisphenol type epoxy resin such as a bisphenol A type epoxyresin or a bisphenol F type epoxy resin; an aromatic glycidyl amine typeepoxy resin such as N,N-diglycidyl aniline, N,N-diglycidyl toluidine,diaminodiphenylmethane type glycidyl amine or amino phenol typeglycidylamine; a hydroquinone type epoxy resin; a biphenyl type epoxyresin; a stilbene type epoxy resin; a triphenolmethane type epoxy resin;a triphenol propane type epoxy resin; an alkyl-modified triphenolmethanetype epoxy resin; a triazine nucleus-containing epoxy resin; adicyclopentadiene-modified phenol type epoxy resin; a naphthol typeepoxy resin; a naphthalene type epoxy resin; a naphthylene ether typeepoxy resin; an aralkyl type epoxy resin such as a phenol aralkyl typeepoxy resin having a phenylene and/or biphenylene skeleton or a naphtholaralkyl type epoxy resin having a phenylene and/or biphenylene skeleton;and an aliphatic epoxy resin such as alicyclic epoxy such asvinylcyclohexene dioxide, dicyclopentadiene oxide or alicyclicdiepoxy-adipate are included. These may be used alone or in combinationof two or more kinds thereof.

These thermosetting resins may contain other components such as a curingagent, an inorganic filler, a curing accelerator, a coupling agent or aninorganic flame retardant when used. In doing so, it becomes possible toappropriately prepare the resin powder having low dust generationproperty which is suitable for various methods of using depending on adifference in characteristics which are required for the resin mixture.

The liquid paraffin included in the resin powder having low dustgeneration property is not particularly limited, however, it ispreferable to include a cycloparaffin. A cycloparaffin is uniformly andeasily mixed with the thermosetting resin, and when a cycloparaffin isset to the resin powder, the degree of the suppression of the dustgeneration property when used can be set to be more excellent.

Moreover, as described in Patent Document 3, an example in which theliquid paraffin is use as a lubricant by combining with thethermoplastics resin was known. However, generally, using the liquidparaffin by combining with the thermosetting resin has not beenconducted.

Second Embodiment

A resin molded article in the present embodiment differs from that ofthe first embodiment in that the resin powder having low dust generationproperty and a filler are dry mixed to manufacture a resin compositionafter the resin powder having low dust generation property including thethermosetting resin and the liquid paraffin is prepared, and a resinmolded article is manufactured from the obtained resin composition.

In addition, also in the present embodiment, as the method ofmanufacturing the resin powder having low dust generation property andthe resin powder having low dust generation property, the same ones asdescribed in the first embodiment can also be used.

Hereinafter, description will be given of a method of manufacturing aresin composition and a resin molded article obtained from the resincomposition according to the present embodiment.

(Method of Manufacturing Resin Composition)

Firstly, the resin powder having low dust generation property andvarious kinds of fillers are dry mixed. Here, dry mixing indicates thatthe resin powder having low dust generation property and the fillerrespectively are mixed without melting. In addition, when the resinpowder having low dust generation property and various kinds of fillersare dried and mixed, each component may be heated, however, a form suchas heating and kneading in which any one of them is melted and kneadedis not used. In doing so, it is possible to obtain the resin compositionaccording to the present embodiment. According to the presentembodiment, since it is possible to suppress the generation of the dustby the powder being diffused to the periphery by using the resin powderhaving low dust generation property, it is possible to prevent theoperation space from being polluted, the resin powder from being mixedinto an operation device, the resin powder from being mixed into otherreagents or the like, which occurs in the related art.

Here, various kinds of fillers are not particularly limited, and forexample, an abrasive grain, an inorganic filler, an organic filler,silica sand, a curing agent, a coupling agent, a rubber, a basematerial, a solvent, a pigment, a fiber, a surfactant, an agglomeratingagent, a hair material, a foaming agent, a glass, an aggregate, carbon,acid and the like are included.

(Method of Manufacturing Resin Molded Article)

The resin composition obtained by dry mixing is not particularlylimited, however, can be used in various methods such as, for example,heating and kneading, melting and molding, hot molding, hot execution,applying onto a base material, fixing onto another manufacturingmaterial or impregnating a base material. In doing so, it is possible toobtain the resin molded article including the resin powder having lowdust generation property according to the present embodiment.

In addition, the resin composition in the present embodiment can be usedas a resin material or a molded material for obtaining various kinds ofresin molded articles described below. The resin composition can beused, for example, as (1) a resin material for obtaining a grindstonesuch as a general grinding wheel, a heavy duty grinding wheel, acutting-off grindstone, an offset grindstone, for treatment of a glasscloth or a diamond grindstone, (2) a resin material for obtaining anabrasive cloth and paper such as an abrasive cloth, an abrasive paper, adisc sandpaper or a buffing, (3) a resin material for obtaining acasting such as a shell molding method (cold coat, semi-hot coat,dry-hot coat), organic self-curing property (cold box, phenol urethane,phenolic acid curing, Lino cure, furan, organic acid ester), a hot box,a shell adhesive agent or a mold washing material, (4) a resin materialfor obtaining a friction material such as a brake lining, a clutchfacing, a disc pad, paper clutch facing or a brake shoe, (5) a resinmaterial for obtaining a rubber such as rubber reinforcement, a hot-meltadhesive agent, an adhesive tape, rubber based adhesive agentcomposition, rubber latex composition, tackifier, a pressure sensitiveadhesive agent, metallic adhesive agent composition, rubbervulcanization or a sealing material, (6) a resin material for obtainingan electric insulation material such as a capacitor coating film or aninsulating varnish, (7) a resin material for obtaining a painting andprinting ink such as a base for painting, an oil-modified paint, a paintfor furniture, a paint for a metal can, a printing ink, offset printing,a dyeing auxiliary or a photoresist, (8) a resin material for obtainingan organic material such as a felt, phenol foam, wood powder mold, aphenol resin fiber, a hard board, a particle board, a reinforced wood oran insulation board, (9) a resin material for obtaining apulp-impregnating product such as beater addition, a battery separator,an air filter or an oil filter, (10) a resin material for obtaining aninorganic fiber-bonding product such as a glass fiber product (a mat ora heat insulation tube) , a rock wool and slag wool product or a fishingrod, (11) a resin material for obtaining a refractory product such as amonolithic material (a mud material, a gunning material, a stampmaterial, a throwing-in material, a pressing-in material or a castablematerial), a shaped material (basic unfiring material, silicon carbidefiring material, a sliding nozzle or a dipping nozzle), a feeder headheat insulation material, a tundish board, a primary aggregate bondingmaterial or a crucible, (12) a resin material for obtaining an adhesiveagent for woodworking such as a plywood (type special), a laminatedlumber or a panel adhesive agent, (13) a resin material for obtaininganother product such as an impermeable carbon product, a carbonaceoussealing material, an electric brush, a sliding material, an activatedcharcoal, an anticorrosion joint agent, an epoxy resin curing agent, acast molding or a phenol FRP.

EXAMPLES Example

(1) Manufacturing Resin Powder having Low Dust Generation Property

Firstly, 1,000 parts by weight of a phenol resin (SUMILITE resin(registered trademark) PR-50731 manufactured by SUMITOMO BAKELITE CO.,LTD.) was put into a 3 L round bottle type separable flask, and meltedby the temperature being raised to 200° C. Moreover, as to the cylindertype separable flask which is used herein, one provided with a stirringdevice, a reflux condenser and a thermometer is used.

Next, 2 parts by weight of the liquid paraffin (MORESCO WHITE P-350Pmanufactured by MORESCO Corporation) was added with respect to the totalweight of the melted phenol resin, and stirred and mixed at 200° C.

Next, the resin which was melted and mixed was taken out to a bat madeof stainless steel, and cooled down at 25° C. (room temperature) toobtain a solid resin. Then, the obtained solid resin was pulverized by aball mill until the average particle diameter of the solid resin becomes30 μm to produce the powder.

(2) Evaluation Method and Result

A cup of powder which was produced was measured out by using a 100 ccplastic cup to drop from 1 m above the ground at 25° C. Even if thepowder produced in this way fell, the generation of the dust almost didnot occur.

Comparative Example

In manufacturing the powder in Example, the powder in ComparativeExample was manufacture without adding the liquid paraffin.

The evaluation of the dust generation property was performed in the sameway as Example. As a result, the dust was intensely generated from theobtained powder.

In this manner, it is possible to obtain the resin powder havingexcellent degree of the suppression of the dust generation property whenused by mixing the liquid paraffin with respect to the thermosettingresin, compared to a case of not mixing the liquid paraffin.

(Manufacturing Resin Composition)

The resin composition was obtained by dry mixing the filler with respectto the resin powders obtained in Example and Comparative Example. Atthis time, the generation of the dust almost did not occur when theresin powder obtained in Example was dry mixed with the filler. On theother hand, as to the resin powder obtained in Comparative Example, thedust was intensely generated when dry mixing with the filler.

(Manufacturing Resin Molded Article)

It was possible to obtain the resin molded article when the obtainedresin powder and resin composition were respectively used, and heatedand kneaded.

Hereinbefore, description was given of the embodiments of the presentinvention, however, these are illustrations of the present invention andit is also possible to employ various kinds of configurations except theabove.

This application claims a priority based on Japanese Patent ApplicationNo. 2012-050015, filed Mar. 7, 2012 and Japanese Patent Application No.2012-236736, filed Oct. 26, 2012, and the disclosures of which areincorporated by reference herein in their entirety.

1. A resin powder having low dust generation property comprising: athermosetting resin; and a liquid paraffin, wherein the average particlediameter is equal to or more than 1 μm and equal to or less than 100 μm.2. The resin powder having low dust generation property according toclaim 1, wherein the thermosetting resin includes a phenol resin or anepoxy resin.
 3. The resin powder having low dust generation propertyaccording to claim 1, wherein the liquid paraffin includes acycloparaffin.
 4. The resin powder having low dust generation propertyaccording to claim 1 comprising: equal to or more than 0.05% by weightand equal to or less than 2% by weight of the liquid paraffin withrespect to the total weight of the thermosetting resin.